1. Field of the Invention
This application relates to systems that measure resistors that define particular accessories, and more particularly to measuring these resistors in accessories attached to mobile devices.
2. Background Information
Different vendors of accessories for mobile telephones and other mobile devices have built-in unique resistors values that identify the different accessories. When attached, the mobile device detects the value of the resistor that identifies the specific accessory. The operation of that accessory may then be executed without further actions by a human user.
Limitations exist when designing systems to measure these resistors. More specifically, the dynamic range of the resistors involved place limitations on minimum currents and/or voltages involved.
It would be advantageous to be able to determine automatically all the possible values of resistors in the external accessories.